#
# This software is Copyright 2005 by Elsevier Inc.  You may use it
# under the terms of the license at http://perl.plover.com/hop/LICENSE.txt .
#



###
### iterate_function
###

## Chapter 7 section 1

sub iterate_function {
  my $f = shift;
  return sub { 
    my $x = shift;
    my $s;         
    $s = node($x, promise { &transform($f, $s) });
  };
}